This proposal describes nmr relaxation measurements on protons, deuterium, and carbon in protein crystals, protein powders and frozen protein solutions which will directly define the state of water in protein systems. Not only will the water state be determined, but the changes in the protein structure brought about by the addition of water to a dry protein system will be investigated. NMR dispersion measurements will be made to define the nature of a low frequency process in semisolid protein systems. The nature of the changes in the protein structure upon crystallization will be investigated directly by observation of the carbon nmr spectrum. The nature of the protein side chain motions will be investigated in the crystal and compared with other protein environments. Preferential solvation of proteins in mixed solvents will be studied by a new nmr technique which promises to provide a rapid screening method for finding effective protein crystallization agents. These magnetic resonance approaches will also be extended to exploration of whole tissues such as muscle or functional subunits of muscle.